Goal is the development of a sol-gel derived, ceramic-like coating for the hermetic protection of microelectronic implant devices. Phase I objective is to evaluate anomalously low surface area Al2O3/SiO2 composition for this application. Specific aims are to determine physical properties of coating as function of sol-gel processing conditions; demonstrate acceptable hermeticity properties for long life applications; demonstrate the ability to adhere the coating to a variety of substrates through a reactive chemistry technology; and demonstrate the potential to solve one critical hermetic protection problem. As established methodology for the preparation of low surface area, sol-gel coatings will be employed. Characterization as a function of chemical composition will include helium displacement density, nitrogen specific surface area, NMR and mercury intrusion pore size, and SEM/TEM. Diffusion to water vapor will be determined. Pull-off tests will evaluate adherence. Interdigitated finger measurements will be practical example. Low surface area and ceramic coating and reactive adherence technologies are both innovations. Successful development will enhance the ability to achieve long life microelectronic implant device capability.